It is very important to control the temperature of the wet and soft corrugated line in the rainy season
It is very important to control the temperature of the wet and soft corrugated line in the rainy season
1. Single side unit temperature control
According to the analysis of the tension in the process of corrugated paper forming, in corrugated forming, the water content of the base paper into the single-sided machine is 9% ~ 12%. According to this principle, it is necessary to make full use of the preheating roller of the single-side machine and the preheating machine and spray device before and after the single-side machine to adjust the water content of the base paper.
If the water content of the base paper is too high, after the temperature of the preheating roller reaches the requirements, the active guide roller of the preheating roller can be adjusted appropriately to increase the preheating wrapping Angle of the base paper and increase the preheating area, which can reduce the water content of the base paper to a certain extent. If the preheating area of the preheating roller is adjusted to the maximum, the water content of the base paper is still too high, then the method of reducing the speed should be adopted to solve.
When the water content of the base paper is too high, sometimes the temperature of the pre-adjusted preheating roller will be reduced, and even can not reach the preheating requirements. At this time, we should increase the boiler steam supply pressure appropriately under the premise of conditions, in order to improve the preheating roller temperature.
If the water content of the base paper is too low, it is necessary to adjust the movable guide roller accordingly, reduce the preheating area, and spray the base paper with the preheating roller and the spray device of the single-side machine to increase the water content of the base paper, so that it meets the standard requirements. In addition, the problem of low water content can be solved to a certain extent by appropriately increasing the speed of the vehicle, thereby reducing the contact time between the base paper and the preheating roller in disguise.
The water content and temperature of the base paper should be measured at any time with a moisture meter, thermometer or pressure gauge, and adjusted according to the measured results. Some data mentioned some "soil" methods, such as observation of the bridge conveyor belt on the single corrugated board, if into a positive ∞ character, you can think of the moisture adjustment of the base paper is better, water content is more appropriate; Another example is that when there is no thermometer, spit saliva on the preheater. If saliva can jump up on the preheater, the temperature has exceeded 150℃, and production can be carried out. But for the purpose of scientific management of production and ensuring product quality, it is advisable to use these methods sparingly. As a formal enterprise, it should reduce the influence of human factors, comply with scientific and accurate data, and manage production.
2 dryer temperature control
The temperature of the dryer directly affects the water content of the final corrugated board. The heating plate of the dryer is generally three groups, each group is composed of four pieces, five pieces and six pieces of heating plate. Each group of heating plates in the steam heated dryer is equipped with a pressure regulating valve, which is used to adjust the steam pressure into the heating plate, so as to change the temperature of the heating plate, to ensure the production of high quality corrugated cardboard. In this process, we need to pay attention to the following details.
Before entering the dryer, the water content will change due to the different length of time the single-sided corrugated board is stored on the bridge. In addition, the single-sided machine paste after a period of use, water content will also change, and then cause the change of water content of single-sided corrugated board. Therefore, before the final composite, the need for secondary preheating of single corrugated board. This preheating process, also according to the size of water content, appropriate adjustment, that is, by adjusting the activity of the guide roll, change the preheating area, to adjust the water content of corrugated board.
The purpose of drying, first of all, is to ensure the curing of the paste, while adjusting the moisture content of corrugated cardboard, both can not be neglected. Therefore, the pressure reducing valve should be adjusted at any time according to the water content of the single corrugated board, so that the dryer can reach an appropriate temperature, which not only ensures the curing of the paste liquid, but also ensures that the final formed corrugated board has moderate water content. In addition, the length of the cooling section of the dryer also has a certain effect on the water content of the board. The cooling section is too short, the moisture can not be volatilized in time, then it is necessary to increase the local air supply volume, in order to achieve the purpose of drying.
